CVE-2026-119197：pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, binary R
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, binary REAL decoding builds a large mantissa one octet at a time by shifting a growing integer and slicing the remaining byte string. Attacker-controlled ASN.1 includes a binary-encoded REAL with a large mantissa and reaches BER, CER, or DER decode(), with or without a schema containing REAL. RealPayloadDecoder.valueDecoder repeatedly performs a left shift, OR, and suffix copy for every mantissa octet, making decode time quadratic in mantissa length. A comparatively small REAL value can hold a decoding worker on one CPU core for seconds or longer and cause availability loss. This issue is fixed in version 0.6.5.
漏洞详情
pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, binary REAL decoding builds a large mantissa one octet at a time by shifting a growing integer and slicing the remaining byte string. Attacker-controlled ASN.1 includes a binary-encoded REAL with a large mantissa and reaches BER, CER, or DER decode(), with or without a schema containing REAL. RealPayloadDecoder.valueDecoder repeatedly performs a left shift, OR, and suffix copy for every mantissa octet, making decode time quadratic in mantissa length. A comparatively small REAL value can hold a decoding worker on one CPU core for seconds or longer and cause availability loss. This issue is fixed in version 0.6.5.
风险评估
- CVSS 评分：7.5（HIGH）
- 评分版本：CVSS 3.1
- 攻击向量：
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
弱点类型
CWE-407
参考链接
- https://github.com/pyasn1/pyasn1/commit/ce3ec3390784780a530047e0e77be5ff457636a4
- https://github.com/pyasn1/pyasn1/pull/132
- https://github.com/pyasn1/pyasn1/releases/tag/v0.6.5
- https://github.com/pyasn1/pyasn1/security/advisories/GHSA-mm57-4v3p-rchx
数据来源：NVD（美国国家漏洞数据库），入库时按 CVSS 评分筛选。
原文链接： CVE-2026-119197：pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, binary R